A New Disease of Picea. 
BY 
A. W. BORTHWICK, D.Sc., 
LECTURER ON FoREST BOTANY, UNIVERSITY OF EDINBURGH. 
With Plate L. 
Picea pungens is one of the most striking and ornamental of our 
exotic conifers, especially in its variety glauca, the light blue- 
green foliage of which at once arrests the attention of the observer 
in parks and policies where it is frequently to be met with. The 
species is one of the Western conifers, its native habitat being 
the Rocky Mountains of North America. It prefers a moist 
situation, but will not stand stagnant moisture, and it is not very 
sensitive in regard to smoke. The slightly bent quadrangular 
needles are seated on prominent cushions of the periderm. They 
are very stiff and sharply pointed. These features can be easily 
made out on Figs. 2 and 3. The buds are fairly large and 
conspicuous. The upper scales are adpressed, while the lower 
ones are prominently recurved. On rubbing the needles a 
peculiar pungent odour is set free. The prickly needles protect 
the tree very effectively against damage by deer and other 
browsing animals. They even protect the buds against the 
attack of squirrels. This species has as yet proved itself to be 
fairly hardy in Europe, being apparently free from any serious 
damage by insects or fungi, but unfortunately it does not appear 
to be entirely immune, as the following account of an apparently 
new fungus-enemy which has attacked it will shew :— 
The fungus was found on a young individual growing among 
other ornamental trees in the pleasure grounds of an estate in 
Perthshire. This tree is shewn in Fig.1. The branches on the 
lower part of the stem were more severely attacked than those 
(Notes, R.B.G., Edin., No, XX, March 1909./ 
